Droughts are too often dismissed as natural occurrences until they can’t be ignored. California’s drought has finally led Governor Jerry Brown to imposed mandatory water rationing for the first time. Meanwhile, in the Southwest, far less water is flowing down the Rio Grande and Colorado Rivers, and a profound water crisis has been growing.

Is philanthropy playing a role in ameliorating the crisis?

The short answer is yes. The longer answer is that a growing number of funders are thinking about water issues in the U.S., which touch on many things that foundations care about, including food supply and wildlife habitats.

Last year, for example, we wrote about how the Pisces Foundation—formed from the wealth of Bob Fisher, one of three heirs to Gap clothing empire—was big into water issues. We noted that Pisces cofounded the California Water Foundation, an initiative of Resources Legacy Fund dedicated to water resources.

A bigger funder who's interested in this area is the Walton Family Foundation, which is the charitable venture of the family that built and still controls Walmart. In recent years, the foundation has quietly become one of the largest funders in American conservation, donating $57 million last year to conservation groups active in marine and river issues.

Of particular note is the $17.4 million the foundation gave last year toward maintaining the health of the Colorado River. The grants are intended to preserve healthy river flows, maintain the quality of the water and restore riparian land for plants, animals and recreational use. Another aim of the grants is to design “structures such as dams and levees in a manner that both serves communities of people and minimizes impacts to rivers and wildlife.”

The Colorado River watershed preservation funding is a good example of "conservationomics," which the foundation describes as a dedication to conservation solutions that make economic sense. The river supplies water to 40 million people in the states of Arizona, California, Colorado, Nevada New Mexico, Utah, and Wyoming. These seven states are in one of the driest parts of the country.

Today, the Colorado Basin’s two primary reservoirs are both showing the consequences of a drought that, in some parts of the region, has now entered its 14th year. Lake Powell, between Utah and Arizona, is now at less than 45 percent of its capacity, while the water in Lake Mead, North America's largest man-made reservoir, is at its lowest level since the Hoover Dam was completed in 1936.

Walton Colorado River grants have gone out a wide variety of groups in the Southwest working on water and river issues, including Arizona Land, Enviromental Defense Fund, the Nature Conservancy, Western Conservation Foundation, Water Trust, Resources Legacy Fund, and Trout Unlimited.

Interestingly, the Walton Family Foundation doesn't say much, at least publicly, about climate change—a key driver of drought and disappearing rivers, which are fed by mountain snowpack. Of course, Walmart the company has been pursuing a variety of efforts to lower its output of greenhouse gas emissions.

At some point, all the funders in the water space will have to look upstream at climate issues.